Finding the center of mass.

How do I find the center of mass of the group of masses? I'm not really sure how to do this, but does it have something to do with having a test mass and finding the direction of the force and different points around the group of masses, and then finding where they intersect? (I'm not sure what maths this would involve too.)

This isn't a homework question, I'm just curious as to how this can be done.

Staff: Mentor

According to wiki:
In physics, the center of mass or barycenter of a system is the average location of all of its mass. In the case of a rigid body, the position of the center of mass is fixed in relation to the body. In the case of a loose distribution of masses in free space, such as shot from a shotgun or the planets of the Solar System, the position of the center of mass is a point in space among them that may not correspond to the position of any individual mass.